As a valve connecting the fuel tank and an external plumbing, there is one shown in Patent Document 1. This valve is made by assembling a fixing housing, a collar, and a valve case. In such valve, the valve case is provided with an elastic locking piece engaged with an upper end portion of the collar, and an annular rib engaged with a lower end portion of this collar, so that the collar is built in an inside of such valve case. By fitting the valve case, in which the collar is built in such a manner, in an inside of a connecting pipe portion of the external plumbing in the fixing housing, the above-mentioned collar is positioned in the inside of this connecting pipe portion so as to reinforce this connecting pipe portion.
However, in such valve, the above-mentioned valve case is required to be provided with the elastic locking piece relative to the collar, and the elastic locking piece relative to the connecting pipe portion of the fixing housing. Also, since the valve case has to be intervened between this connecting pipe portion and the collar, it was inappropriate from the standpoint of ensuring a flow channel for fuel in the inward of this connecting pipe portion as widely as possible.